When to Plant Brussels Sprouts in St. Mary Parish, LA
May in the garden — St. Mary Parish, Louisiana
We've pulled the most time-sensitive tasks for St. Mary Parish, Louisiana this May and put them front and centre. Tackle them in order.
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Start harvesting brussels sprouts
Taste as you pick. The first ripe produce is the best feedback loop you'll get all season.
A few tasks this May that'll pay off in June
- First harvests: brussels sprouts
Brussels sprouts are a cold-hardy brassica that produces miniature cabbage-like heads along a tall stalk. Flavor improves after a light frost.
St. Mary Parish, Louisiana is in USDA Zone 9b. The average last spring frost is February 14 and the first fall frost is December 5, giving you a growing season of approximately 294 days.
At an elevation of 252 feet, St. Mary Parish receives approximately 48.5 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 95°F, so Brussels Sprouts may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Brussels Sprouts will need more frequent watering and organic matter to retain nutrients.
St. Mary Parish Soil Profile
Soil Type
Sandy Loam
Soil pH
4.8-6.4
Drainage
Well Drained
Plant Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Soil Compatibility in St. Mary Parish
How your county's soil matches Brussels Sprouts's growing requirements.
Soil pH
Your soil pH (4.8–6.4) is more acidic than Brussels Sprouts prefers (6.0–7.5). Add garden lime to raise pH.
Soil Texture
Sandy soil in St. Mary Parish warms quickly in spring but drains fast. Brussels Sprouts will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Brussels Sprouts.
Organic Matter
Organic matter is moderate (2.0%). Annual compost additions will help Brussels Sprouts.
How to Plant Brussels Sprouts
Fall planting: Sow 8 weeks before your first frost date for a fall harvest.
Plant Water Budget
Water stress score is 6/10 — consider drought-tolerant varieties and mulching
Monthly Watering Guide for Brussels Sprouts
Brussels Sprouts needs approximately 0.9 inches of water per week (3.9" per month). Here's how your county's rainfall compares month by month.
| Month | Brussels Sprouts Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3.6" | 0" | ❄️ Dormant |
| Feb | 3.9" | 3.4" | 0.5" | 💧 Light watering |
| Mar | 3.9" | 5.1" | 0" | ✅ Rainfall sufficient |
| Apr | 3.9" | 3.8" | 0.1" | 💧 Light watering |
| May | 3.9" | 3.8" | 0.1" | 💧 Light watering |
| Jun | 3.9" | 3.6" | 0.3" | 💧 Light watering |
| Jul | 3.9" | 5.6" | 0" | ✅ Rainfall sufficient |
| Aug | 3.9" | 5.1" | 0" | ✅ Rainfall sufficient |
| Sep | 3.9" | 3.5" | 0.4" | 💧 Light watering |
| Oct | 3.9" | 3.1" | 0.8" | 💧 Light watering |
| Nov | 3.9" | 3.9" | 0" | ✅ Rainfall sufficient |
| Dec | 3.9" | 4.2" | 0" | ✅ Rainfall sufficient |
Water needs are for active growing months only (Feb–Dec in St. Mary Parish). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Brussels Sprouts Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Brussels Sprouts Planting Timeline — St. Mary Parish, LA
Brussels Sprouts Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 17 | Jan 17 – Jan 31 |
| Transplant Outdoors | February 14 | Feb 14 – Feb 28 |
| Direct Sow | January 24 | Jan 24 – Feb 14 |
| Harvest | May 16 | May 16 – Jul 11 |
| Fall Sowing | October 10 | Oct 10 – Oct 24 |
Plant 1" deep · 15" apart · Rows 24" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors Direct Sow |
| February | Transplant Outdoors Direct Sow |
| March | — |
| April | — |
| May | Harvest |
| June | Harvest |
| July | Harvest |
| August | — |
| September | — |
| October | Fall Sowing |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
0.9"/week · Natural rainfall sufficient
📅 Days to Maturity
90–130 days
🧪 Soil pH
Needs 6–7.5 · Your soil: too_acidic
🗺️ USDA Zone
Zone 9b
📆 Growing Season
294 days in St. Mary Parish
Growing Tips for Brussels Sprouts in St. Mary Parish
Direct sow Brussels Sprouts outdoors after February 14 in St. Mary Parish when soil has warmed and frost danger has passed.
Sandy soil in St. Mary Parish dries quickly — mulch Brussels Sprouts with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
Summer highs in St. Mary Parish reach 95°F — grow Brussels Sprouts as a spring or fall crop. Use shade cloth if planting in summer.
Common pests for Brussels Sprouts in this region include cabbage worm and flea beetles. Use row covers early in the season and inspect plants weekly.
General growing tips
Start seeds indoors 12-14 weeks before first fall frost. Stake tall plants to prevent toppling. Remove lower leaves as sprouts develop to improve air circulation.
Companion Planting
Good Companions
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Brussels Sprouts in Other Locations
Frequently Asked Questions
When should I plant Brussels Sprouts in St. Mary Parish, LA?
St. Mary Parish is in Zone 9b with an average last frost of February 14. Plan your Brussels Sprouts planting based on this frost date — see the calendar above for exact timing.
What planting zone is St. Mary Parish, LA?
St. Mary Parish, Louisiana is in USDA Hardiness Zone 9b. The average last spring frost is February 14 and first fall frost is December 5.
Your St. Mary Parish Garden Planner — Free
A 24-page printable planner built for St. Mary Parish (Zone 9b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.